1. Technical Field
The present invention relates to a substrate unit, a liquid crystal display unit including the substrate unit, and an electronic apparatus.
2. Description of the Related Art
Display apparatuses and electronic apparatuses such as a portable electronic apparatus include a substrate unit including a substrate provided with an electronic circuit or wiring (wiring substrate, and a circuit board), and a flexible substrate coupled to the substrate. In a case of the display apparatus, a substrate provided with a drive circuit of a liquid crystal panel is coupled to a control circuit that outputs an image signal via a flexible substrate. Also provided is a touch detection device that can detect an external proximity object, what is called a touch panel. A substrate provided with a detection electrode of the touch panel may be coupled to the flexible substrate.
As a method of coupling the substrate to the flexible substrate, as disclosed in Japanese Patent Application Laid-open Publication No. 2009-224505, an anisotropic conductive film (ACF) is arranged between the substrate and the flexible substrate and is crimped and coupled using a crimping head.
Japanese Patent Application Laid-open Publication No. 2004-95872 (JP-A-2004-95872) discloses a structure in which both of the substrate and the flexible substrate configure one circuit to be conducted when the substrate and the flexible substrate are joined, and allows a coupling state between the substrate and the flexible substrate to be detected to easily and quantitatively detect the coupling state when the substrate is coupled to the flexible substrate.
As disclosed in JP-A-2004-95872, by providing a circuit for detecting the coupling state on the substrate and the flexible substrate, the coupling state of the substrate can be detected in detecting a conductive state. However, with the structure disclosed in JP-A-2004-95872, conduction may be caused even when a crimp by the crimping head is insufficient.
For the foregoing reasons, there is a need for a substrate unit, a liquid crystal display unit and an electronic apparatus that can detect a coupling state between a substrate and a flexible substrate in more detail.